1. Field of the Invention
The present invention is related to an Influenza A H1N1 subtype-specific aptamer and applications thereof.
2. The Prior Arts
Influenza, or sometimes abbreviated as flu, is an acute respiratory infection caused by influenza viruses. Influenza viruses can spread through aerial and contact infection, therefore, by the advance in transportation and the increase in travel, business, and social interactions, cyclical pandemics occurs throughout the globe, for instance the 1918 Spanish flu and the 1968 Hong Kong flu. Symptoms of influenza include running nose, sore throat, cough, as well as fever, headache, muscle ache, fatigue, etc. Symptoms of influenza are acute and would usually lead to complications, thus, for groups such as the elderly, children, and patients with immunodeficiency, influenza is likely to result in more server symptoms, for example, pneumonitis or cardiorespiratory failure, and even death.
Influenza viruses can be categorized into 3 types: type A, B and C, wherein the type A influenza virus is further subcategorized into many subtypes such as H1N1, H3N2, and H7N9, according to the two types of glycoprotein on the envelope, namely Hemagglutinin (H) and Neuraminidase (N). The threat of influenza lies in its rapid breakout, widespread infection and the possibility of causing sever complications; particularly, type A influenza is the most likely to cause regional epidemic or worldwide pandemic among all other influenzas. Besides, the type A influenza virus is able to cross-infect and recombine between different species, for example, human, swine, and bird, which increases the difficulties of treatment and prevention.
Therefore, early diagnosis and prevention of influenza are vital. The methods of detection for influenza virus infections commonly used nowadays include viral culture, viral nucleic acid detection, serology testing, and rapid influenza diagnostic test. These methods are usually time-consuming with low sensitivity/specificity and require large amount of sample or expensive reagents. Although, rapid influenza diagnostic test is able to obtain result in a short time in a simple manner without the use of special equipment and is able to be performed in clinic or ward, its low sensitivity is likely to cause false negative results and is unable to accurately distinguish the type and subtype of the influenza viruses detected. On the other hand, antibodies with specificity for influenza viruses are often used clinically for detection of influenza virus. Although those antibodies have specificity to influenza viruses, the antibodies themselves are very sensitive to conditions of the surrounding environment such as temperature and moisture, thus, are easy to lose activity and cause inconvenience when transport, store, or use. Furthermore, since antibodies are prepared in batch, activity of antibody is not identical among batches, while errors are likely to occur when operating antibodies due to manual mistakes or effects of the environment of the operation.
Prevention and accurate diagnosis are critical in terms of public health and disease control. Furthermore, accurate diagnosis is the foundation of effective treatment. However, currently the market still lacks an accurate, cost-effective, easy-to-store, and highly efficient method for influenza virus detection.